In my limited experience with these haveing a 257 wby and a 25.06 I think velocity has a lot to do with how they perform. And the heavier bullets do not like the higher speeds from my experience
Both of mine shoot best with 100 gr bullets. The 110 AccuBond does well but not as good as the 100s and I have never shot anything any lighter as they are deer guns
I have not had any problem with a number of 25-06's with 87 through 120 gr bullets in getting exceptional accuracy when you find the right load. In my currant 26" SS Shilen barrel 1-10 twist 25-06 which does not like boat tail bullets but will shoot flat base like a house a fire. My most accurate load with 117 Sierra Pro Hunters is 49 grs IMR 4350, CCI 250 primer, Rem case, 3000 fps. It will put 5 shots in 3/4" at 300 yards. It took the CCI 250 primer to get this accuracy. With different make primers I could not get 3/4" groups at 100 yards but the switch to the CCI 250 started shooting bug holes at 100.
I have had two barrels on my 25-06 and have a new .257 Wby Mag. All of them have had 1 in 10 twists. I like to experiment and have tried most of the .257 caliber offerings out there.
I have had good luck getting good groups with bullets from 75 to 120 grains. Sometimes it took a little trial and error to get there, but they have all shot pretty well for me. Like 1 Shot, both barrels on my 25-06 have shot flat base bullets better than boattails.
Recently, though, I tried the 115 grain Barnes TSX in my .257 Wby Mag. I know, Barnes recommends a 1 in 9 twist or tighter for this bullet. However, my dad shoots them sometimes in his identical .257 Wby Mag with good results. My dad shoots them at 3450 fps and I think this is the key to his success. When I tried them in my personal .257 Wby Mag I only got up to 3300 fps before I just gave up on them.
My starting loads with the 115 TSX made shotgun pattern size groups with bullets holes that were clearly oblong, those bullets were keyholing badly.
As I increased the powder charge the groups got better. At 3300 fps the group was an inch for three shots but the holes were still oblong. I decided that even if I increased the speed, I would still be wondering what that bullet would do at long range.
I actually went completely the other direction and tried the 80 grain Tipped TSX. With H4350 powder I have those bullets going 3800 fps and am getting great groups. I indend to try this load on antelope in New Mexico this year. Last year I watched as my dad shot an antelope buck at 586 yards with his .257 Wby Mag using those 80 grain TTSX bullets at 3850 fps. That buck never even kicked, he was dead before he hit the ground.
Having said all this, my favorite bullets for the .257 caliber rifles are the 100 grain Nosler Partition and the 100 grain Barnes TSX.
